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61.
One major limitation in the use of body feathers of seabirds as a monitoring tool of the trophic structure and contamination levels of marine ecosystems is the degree of heterogeneity in feather chemical composition within individuals. Here, we tested the hypothesis that moulting patterns drive body feather heterogeneity, with synchronous moult minimizing within-individual variations, in contrast to asynchronous feather growth. Chicks of white-chinned petrels Procellaria aequinoctialis (representative of bird chicks) and adults of king penguins Aptenodytes patagonicus (representative of adult penguins) that moult their body feathers synchronously showed very low within-individual variations in their feather δ13C and δ15N values and mercury (Hg) concentrations. By contrast, body feathers of adults of Antarctic prions Pachyptila desolata (representative of adult seabirds with asynchronous feather growth during a protracted moult) presented much higher within-individual variances for the three parameters. These findings have three important implications for birds presenting a synchronous body moult. (1) They suggest that all body feathers from the same individual have identical δ13C and δ15N values and Hg content. (2) They predict negligible within-individual variations in the body feather values of other useful stable isotopes, such as δ2H and δ34S, as well as in the concentrations of other compounds that are deposited in the keratin structure. (3) Analysis of one or any number of pooled body feathers is equally representative of the individual. In conclusion, we recommend that long-term routine monitoring investigations focus on birds presenting synchronous rather than asynchronous moult of body feathers both in marine and terrestrial environments. This means targeting chicks rather than adults and, for seabirds, penguins rather than adults of flying species.  相似文献   
62.
Many studies comparing the behaviour of individuals of different genders or species showed that animal body mass and forage quality/quantity are key elements of the foraging ecology of herbivores. Since body mass could also influence the animal’s sensitivity to predation risk, its vigilance behaviour should consequently be affected. Alpine ibex (Capra ibex) is characterised by a strong dimorphism among males of different ages, thus representing an ideal case study for testing the Jarman-Bell principle, avoiding possibly misleading effects resulting from the comparison between different species or genders. We analysed the fine-scale foraging behaviour of male ibex in order to assess the effect of body mass and the effects of vegetation quality/quantity on both foraging and vigilance behaviour. Our results showed that smaller males were more selective than larger ones, on account of their lower capability of digesting plant. Smaller males scanned the environment more frequently than larger ones. Male ibex grazed more selectively in sites with high quality forage and their bite rate increased as forage biomass decreased. Vigilance frequency increased with increasing forage biomass as, under these circumstances, ibex are able to prolong anti-predator vigilance while chewing bites that have already been cropped. Our findings highlight the effects of body mass per se on both foraging and anti-predator behaviours in herbivores, thus supporting the Jarman-Bell principle. Foraging can arguably be considered a very flexible behaviour with high evolutionary relevance as it enables herbivores to optimally adjust their total energy intake under varying conditions of food resources.  相似文献   
63.
Badges of status, usually color patches, are hypothesized to serve as important signals within natural populations by communicating an individual’s fighting ability or aggressiveness before an interaction ever takes place. These signals, which may evolve via sexual and/or social selection, mediate intra-specific competition by influencing the outcome or escalation of contests between individuals. The last 10 years saw the rise of interest in the role of ultraviolet (UV)-based coloration in intra-sexual communication. However, the rare experimental studies that tested this hypothesis found opposite results, which may originate from the different methodological procedures used to assess the badge of status theory. We present here the results of an experiment testing whether male blue tits (Cyanistes caeruleus) respond differently to unfamiliar conspecifics presenting contrasted UV crest coloration. In an aviary, we simultaneously presented two caged blue tits with enhanced (UV+) or reduced (UV−) crest coloration to a focal bird. We found that focal males acted more aggressively towards the UV− males than UV+ males. In addition, focal males fed more often close to males that were similar in brightness or duller than themselves. We conclude that, in blue tits, UV blue crest coloration affects both social and aggressive responses towards unfamiliar individuals, and thus it has some properties of a badge of status.  相似文献   
64.
65.
The Amazon Delta and Estuary (ADE) is a region of continental and global ecological importance. Controversy, many of the basic infrastructure and services essential for quality of life and sustainable development of this delta are absent. Using a conceptual model to define socio-economic vulnerability in the urban ADE, a thorough assessment of indicators including sanitation services, housing conditions, household income, population, flood risk and unplanned settlements was conducted in 41 cities at the census sector scale (n = 2938). A multi criterion index was applied to classify urban vulnerability from three dimensions: flood exposure, socio-economic sensitivity and infrastructure. This is the first study to examine urban vulnerability within and between urban areas of the ADE. Results indicated that most of the urban sectors of the ADE are exposed to potential risks due to a combination of flood hazards, poverty and basic structural deficiencies such as insufficient drinking water or inadequate waste water collection, with several sectors being afflicted by similar problems. The assessment of vulnerability indicates that 60–90 % of the urban population live in conditions of moderate to high degree of vulnerability. The ADE cities presented a pattern where vulnerability increases from city center to their newly developed urban areas. Inadequate planning coupled with rapid urbanization has contributed to the development of unplanned settlements in almost half of the urban sectors of the ADE. Combined, these factors contribute to widespread socio-economic vulnerability along the urban spaces of the ADE, increasing exposure to health risks and more frequent seasonal and stochastic events such as storm surges and high flooding levels.  相似文献   
66.
Mercury (Hg) in fish can present a potential risk to wildlife and human consumers. Mercury levels were determined in 12 fish species and 2 invertebrate species from the French coast of the Eastern English Channel collected in June and November 2012. Total mercury concentrations in the muscle tissues ranged between 0.04 and 1.63 µg g-1 (d.w.). Dab and sandeel displayed a significant positive correlation between Hg concentrations and fish length. Seasonal differences in Hg concentrations were observed for dab and shrimp. The lesser weever showed significantly higher concentrations of Hg (0.97 ± 0.34 µg g-1 d. w.) than all other species. Gobies and sprat, which had the smallest size, showed significantly lower concentrations than herring, whiting, pout and sardine. Among the considered species, flatfish such as dab, flounder, plaice and sole displayed intermediate levels of Hg. In the present study, the fish age expressed as specimen length seems to be one of the major factors governing Hg contents in muscle tissues. Finally, mercury concentrations in commercial fish from the Eastern English Channel were below the levels fixed by the European Union for total mercury in edible parts of fish products.  相似文献   
67.
68.
How is young people's pro-environmental orientation related to their parents' pro-environmental values, attitudes, and behaviours? To answer this question, we examine parent–child similarities of general values as well as specific attitudes and behaviours related to three common household practices: purchasing environmentally friendly products, curtailing electricity use, and handling waste responsibly in a sample of 601 Danish families. Significant and positive, but weak correlations between parents' and children's values are found across all of Schwartz's ten value domains. The parent–child correlations are stronger for specific pro-environmental attitudes and behaviours. The positive correlations suggest that family socialization exert a significant influence on young consumers' pro-environmental orientation. Still, the young generation is, on average, significantly less environmentally concerned than their parents' generation. Implications of these findings are discussed.  相似文献   
69.

Introduction

The purpose of this investigation was to compare the results of a web-based and a telephone interview survey measuring driver concerns about a variety of traffic safety issues, their beliefs, and specific driving behaviors.

Method

State-wide, annual random digit-dial telephone surveys and web-based surveys were conducted in Maryland. A total of 1,700 drivers were surveyed by telephone and 6,806 took a web survey.

Results

Telephone respondents were more likely to be female and older. Web respondents were more likely to be white and not Latino/Hispanic. After controlling for demographic differences, telephone survey respondents were more likely to be concerned about traffic safety. They were more likely to believe that sobriety checkpoints reduce drunk driving (OR = 2.18, 95% CI 1.94, 2.45), they would be ticketed for not wearing a seat belt (OR = 1.26, 95% CI 1.12, 1.43), and they would be stopped by the police if they drove after drinking too much (OR = 1.17, 95% CI 1.03, 1.32). They were less likely to report a variety of risky behaviors including using a cell phone while driving (OR = .54, 95% CI .48, .61) and driving 10+ mph over the speed limit (OR = .81, 95% CI .72, .91), but were more likely to report having been ticketed for a moving violation in the last month (OR = 2.22, 95% CI 1.70, 2.90). Suggestions are offered for overcoming potential sources of sampling bias.

Impact on Industry

Web-based surveys produce substantially different results than random-digit-dial telephone surveys, when used for public assessments of traffic safety concerns and behaviors.  相似文献   
70.
Many authors have suggested that Indigenous communities are especially vulnerable to the direct and indirect impacts of climate change, yet there remains a paucity of fine-grained geographic data on the particular impacts of climate change on specific places and on local communities, especially Australian Indigenous communities. While there are some recent studies being undertaken with Australia's Torres Strait Island people, our research takes up the issues of vulnerability and resilience with two Indigenous communities from different environments on the mainland in North Queensland. They are the Aboriginal peoples of the rainforest and reef environments of the Wet Tropics and the Aboriginal people of the discontiguous rainforest, grasslands, dry forests and marine environments of Cape York. The results demonstrate variability in their understandings of climate change and in their capacities to anticipate and manage its impacts, while at the same time illustrating some common held themes about environmental and cultural values, observed environmental change, attributions of cause and effect, and of climate in general.  相似文献   
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